The present invention relates to an apparatus for aligning a semiconductor wafer with an inspection contactor, and more particularly, to an apparatus for achieving alignment between a semiconductor wafer and an inspection contactor, whereby a plurality of contacts formed on the contactor and their corresponding electrode pads of each of a plurality of chips formed on the wafer are aligned when they are connected electrically to one another by being brought collectively into touch with one another.
Manufacturing processes for semiconductor wafers include an inspection process in which a large number of IC chips that are formed on the surface of each semiconductor wafer (hereinafter referred to simply as "wafer") are subjected to various electrical inspections without changing the wafer conditions. In this inspection process, nondefective wafers that carry no defective chips thereon are sorted out. (defective ones with defective IC chips thereon.) Only the non-defective wafers are subjected to the next process, such as a semiconductor device assembling process, whereupon individual semiconductor devices are completed as products. Thus, the yield of the products is improved. In a typical example of the inspection process, the individual IC chips are inspected by successively bringing the electrode pads of each IC chip into touch with probes of a probe card. In another example, all the IC chips of each wafer are simultaneously inspected in one lot by bringing all the electrode pads corresponding to the IC chips and a plurality of contacts of an inspection contactor (hereinafter referred to simply as "contactor") corresponding to the pads into touch with one another at a time.
According to the latter process in which the IC chips of each wafer are inspected collectively, the contactor and the wafer are opposed to each other, and a plurality of bumps, as references for the contactor, and their corresponding electrode pads, as references for the wafer, are successively aligned with one another in a manner such that their respective positions are visually observed to be ascertained. The bumps and the electrode pads are brought collectively into touch with one another after they are aligned with success. After this is done, the electrical inspections are conducted by using specific inspection devices, and the chips of the wafers are checked for conformity. Based on the result of this check, non-defective wafers are distinguished from defective ones.
Conventionally, the bumps of a contactor and the electrode pads of a wafer are aligned under visual observation, as described above. Accordingly, aligning the bumps and their corresponding electrode pads is not an efficient operation, costing an operator prolonged labor and increasing the operator's burden. Since the accuracy of alignment varies depending on individual operators, moreover, it is difficult to obtain a steady state of constant.